Currently, as a sensor used for analyzing tongue movements in the oral cavity in masticating and swallowing, there is known a tongue pressure sensor which is attached to a palate (the upper wall in the oral cavity) of a subject and which is configured to analyze tongue movements by measuring pressure at the time when the tongue comes into contact with a pressure-sensitive sensor arranged at a predetermined position of the palate (see, for example, Patent Literature 1). In practice, the tongue pressure sensor includes a base section attached to the palate, and a strip-like branch section branched from the base section and similarly attached to the palate, and has a configuration in which a plurality of pressure-sensitive sensors are provided at each of the base section and the branch section.
Here, the pressure-sensitive sensor used for the tongue pressure sensor is configured such that two pressure-sensitive ink layers are arranged so as to face each other via a predetermined gap, and such that, when a pressure is applied to the side of the palate by the tongue, the two pressure-sensitive ink layers are brought into contact with each other by this pressure so that electric resistance values (also referred to as a resistance value) of the two pressure-sensitive ink layers can be changed. Thereby, the analysis of tongue movements can be performed in such a manner that the tongue pressure sensor detects the pressure applied to each of the pressure-sensitive sensors and the position of the applied pressure by measuring a change of the electric resistance value of the pressure-sensitive ink layer of each of the pressure-sensitive sensors.